Honestly, I can see the intend of the toxicon mechanic. As someone who plays only on a casual level, I'd gladly sacrifice a gcd if it meant I can shield a non-tank party member from getting hit (which happens A LOT in dungeons and alliance raids), since that's what shields are for, but I can also see how it's essentially worthless for the raiding environment.

While I'm no fan of homogenization in general, and Twelve know healers are the ones that need it the least, I think it'd make sense if Toxicon becomes Sage's version of Misery - get adderstings as a reward for shielding, get 3 stacks and you get a big boom spell.